1) It's length is 2-3m at best, enough to trap the opponent. You can however create it from short to mid range.You must be registered for see images
To what length can the wall be created?up to short or mid?
2.Couldn't find a picture of it but am pretty sure i get what it looks like.
Q: can it be used to defend from attacks from an upward direction?
2) You collect the dust and make the wall in front of you, so I'm afraid you won't be able to defend against attacks from above.